Now, there's an endearing video of the astronauts, including #YearinSpace's Scott Kelly and Kjell Lindgren, munching happily at their homegrown lettuce:

The space lettuce was grown during NASA's experiment Veg-01, which aimed to allow astronauts to grow and eat their own food during deep space missions. In this program, rooting "pillows" with seeds in them are activated by an astronaut. They are then watered, tended to, and harvested after 33 days. Then it can be eaten, at least after the astronauts sanitize it with citric acid, and apparently it tastes something like arugula.

This project allows the astronauts to grow their own food and produce fresh air on longer missions. It will be especially important to NASA's long-term plans, as giving astronauts the ability to grow their own food will be essential once we begin to plan a long-duration trip to Mars and other deep space locations, and especially if we ever plan to colonize another planet.

"If we're ever going to go to Mars someday, and we will," Kelly says in the above video, "then whenever that is, we are going to have to have a spacecraft that is much more self-sustainable with regards to our food supply."